This resubmission application requests funding to support the purchase of a 3 Tesla Siemens MAGNETOM Skyra MRI system at the Athinoula A. Martinos Center for Biomedical Imaging. The proposed instrument, which will upgrade the Martinos Center's existing 11-year-old 1.5 Tesla Siemens Avanto scanner, will be dedicated for whole-body human MRI research and will support the funded research of a large and growing community of clinical/translational investigators at the Massachusetts General Hospital and neighboring institutions. The need for the proposed 3T MRI system has a number of facets. First, the existing 1.5T scanner no longer provides the technological edge to drive our investigators' research to the next level. Higher field strength provides better image quality, and greater sensitivity to the subtle differences in brain structure or function that may characterize significant physiological and pathological differences. In recognition of the benefits of scanning at 3T versus 1.5T, the clinical/translational investigators within our community have increasingly transition their studies to 3T. However, as their numbers and their research grow, the Center's ability to accommodate demand is also increasingly challenged. Although the Martinos Center has the great fortunate of having several research-dedicated 3T MRI systems already on site, each has a specific defined research mission that includes development of high-N RF array coils and gradient technologies (Bays 3 and 4, respectively). Because the ongoing technology development work means these systems often undergo hardware modifications, they do not offer the stability needed to support longitudinal clinical research. As a result, broadly, clinical and translational research studies are hindered by a variety of factors that include a shortage of available scan time, instability for longitudinal clinical studies. The proposed instrument will not only enhance the ability of clinical/translational investigators to conduct their current research, it will also provide opportunities for fruitful new projects and collaborations. With the patient-friendly imaging environment of the proposed instrument brought to bear on these projects, we anticipate that the broad and active growing community of clinical/translational scientists engaged in MRI-based studies of major human disorders will be poised to find exciting new diagnostic and therapeutic applications relevant to a many neurological and psychiatric diseases. PUBLIC HEALTH RELEVANCE: Imaging technologies such as MRI have enabled clinical investigations to better characterize human disease and, thus, inform the development of more improved treatment. Newer-generation technologies designed for patient-friendly operation offer dramatic improvements in image quality to better detect the physiological subtleties that may differentiate health from disease, and in turn advance understanding of human disease to optimize patient care. We purpose to upgrade our aging clinically oriented MRI scanner in order to leverage critical cutting-edge advances in MRI technology to support ongoing and developing areas of clinical research at the Massachusetts General Hospital.